package com.bdqn.controller.common;

import com.bdqn.util.RespBean;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.UUID;

/**
 * 文件上传和下载的controller
 */
@Slf4j
@RestController
@RequestMapping("/common")
public class CommonController {
    @Value("${reggie.path}")
    private String basePath;

    /**
     * 文件上传
     * @param file
     * @return
     */
    @PostMapping("/upload")
    public RespBean upload(MultipartFile file) {
        //file是一个临时文件 需转到存储位置 不然请求完成会丢失
        log.info(file.toString());
        //存到磁盘的某个文件夹中
        File file1 = new File(basePath);
        //判断当前目录是否存在  不存在的话进行创建
        if (!file1.exists()) {
            file1.mkdirs();
        }
        String fileName = "";
        try {
            //拿到原先的图片名字
            String originalFilename = file.getOriginalFilename();
            String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));
            //使用UUID/时间戳 重新生成文件名 防止文件名称重复造成文件覆盖
            fileName = UUID.randomUUID().toString() + suffix;
            file.transferTo(new File(basePath + fileName));
        } catch (IOException e) {
            e.printStackTrace();
        }
        //把图片的名称返回 因为后续会用到
        return RespBean.ok("文件上传成功", fileName);
    }

    /**
     * 文件下载
     *
     * @param name
     * @param response
     */
    @GetMapping({"/download",})
    public void download( String name, HttpServletResponse response) {

        try {
            //输入流，通过输入流读取文件内容
            FileInputStream fileInputStream = new FileInputStream(new File(basePath + name));

            //输出流，通过输出流将文件写回浏览器
            ServletOutputStream outputStream = response.getOutputStream();

            response.setContentType("image/jpeg");

            int len = 0;
            byte[] bytes = new byte[1024];
            while ((len = fileInputStream.read(bytes)) != -1) {
                outputStream.write(bytes, 0, len);
                outputStream.flush();
            }
            //关闭资源
            outputStream.close();
            fileInputStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}